Well I just finished my first battery drain. I used the phone non-stop for 5 hours mix of GPS and wifi, recieving about 45-50 emails pushed through google, 10 minute twitter upates with Seesmic, downloaded 15 apps, and surfed for a bit over an hour and a half. Not to mention setting the phone up, syncing with google, then forcing it to sync with google a handful of times while I figured it out. Down loaded and played 6 different games, Etc etc etc. It was down to 25% when I put it on the battery charger for the second cycle. If I would have used up the remaining 25% I could have pushed it out to 7 hours I figure, that is if I wanted to totally kill the battery. And that was on the very first charge I put on the battery. I unpacked the phone, put the battery in, plugged it into the wall for a bit over 2 hours, then booted activated the phone and messed around. Hell I even had all the battery tweaks not done like turning networks, gps, and wifi off, not to mention live wallpapers. The way I figured it I had this thing turn to the worst battery sucking state I could shy of turning on bluetooth.
I figure by the 5th or 6th cycle and normal usage I should be able to pull 10 hours, maybe a bit more out of the battery. It's about on par with my Storm, I could go 10-12 with the Storm.
I'm beginning to wonder if most of the people having battery issues are using only the straight usb to computer cable or if they are using the wall plugin, and the state of their phone while charging. I have seen people with stock batteries report anywhere from 4 hours and it's dead all the way up to 1 1/2 days without a charge. Pretty wide spread field if you ask me.
If you hate the phone take it back, you have 30 days....simple enough solution, don't complain about what updates they are coming out with just be glad they are doing it. If something is wrong software wise with the phone it will be fixed.